Electron discharge device



April 3@, m3;

c. I. BAKER ELECTRON DISCHARGE DEVICE Filed Oct. 23, 1931 LQEEEM 29lNl/EA/TOR CJBA/(ER ATTORNEY Patented Apr. 36, 1935 UNlTED STATES PATENTOFFICE Telephone Laboratories, York, N. Y., a corporation Incorporated,New of New York Application October 23, 1931, Serial No. 570,531 10claims, (01. 250-275) This invention relates to electron dischargedevices and more particularly to an electrode assembly in such devices.

The static and dynamic characteristics of electron discharge devices arelargely dependent upon the space relation of the several electrodes. Anychange in this relation, particularly such changes as are occasioned bymechanical and acoustic shocks to which the device may be subjectedduring operation, produce objectionable microphonic disturbances whichresult in unfaithful and distorted reproduction.

An object of this invention is to prevent external disturbances fromaffecting an electron discharge device.

Another object of this invention is to unify the electrode assembly inelectron discharge devices and to facilitate the fabrication thereof.

In one embodiment of this invention an elec-' tron discharge devicecomprises an enclosing vessel having a stem and a unitary electrodeassembly resiliently supported from the stem. The electrode assemblyincludes a rigid anode which supports twin insulating members at eachend thereof, and a cathode and grid supported by the insulating memberswithin the anode. A pair of uprights extend from the stem and carryspring members which are secured to the electrode assembly near one endthereof. Other spring members are mounted on supports extending from thestem and are secured to the other end of the electrode assembly. Thespring members may be of electrically conductive material and may beutilized as connecting links between the electrode leading-in wires andthe electrodes. Furthermore, the spring members may also be so designedby selection of the material and elasticity thereof that the electrodeassembly will have a predetermined natural frequency of vibration, suchas the resonant frequency of a circuit in which the device is to beutilized.

The invention will be understood more clearly and fully from the followlg detailed. description with reference to the accompanying drawing:

Fig. 1 is a perspective View of an electron discharge device made inaccordance with this invention with portions of the enclosing vessel andthe anode broken away to show the inner electrode structure moreclearly;

Fig. 2 is another perspective view from a different angle of thedischarge device shown in Fig. l with a portion of the enclosing vesselbroken away, showing the resilient mounting of the electrode assemblywithin the enclosing vessel;

Fig. 3 is an end plan view of the electrode unit assembly Showing therelation of the electrodes and the supports at one end of the unit;

Fig. 4 is another end plan View of the electrode unit assembly at theopposite end of the unit; and

Figs. 5 and 6 are enlarged detail views showing 5 the attachment of thespring members to the supports and to the electrode assembly.

Referring now to the drawing, an electron discharge device, in oneembodiment of this invention, comprises an enclosing vessel l0 having a10 reentrant stem l l which terminates in a substantially rectangularpress l2. The vessel I0 is secured, as by cementing, to an insulatingbase l3 carrying terminal prongs 14 (only one of which is shown) forassociating the device with an elec- 15 trical' circuit. A plurality ofrigid rods l5 and I6 having parallel portions extending lengthwise ofthe vessel Ill are embedded in the press l2 and together with aplurality of bent wires H and it support a unitary electrode assembly. 2

The electrode assembly comprises a flattened cylindrical anode l9, andM-shaped filamentary cathode 2i], and a helical control electrode orgrid 2i encircling the cathode and uniformly spaced between the cathodeZ0 and the anode [9. The 25 anode I 9 may be of carbonized nickel or anysuitable conductive material and comprises two similar plate portionshaving integral flanges 22 joined together, and provided with parallelspaced ridges or embossments 23 for increasing the rig- 3 idity of theanode to prevent undesirable and excessive distortion or bucklingthereof due to temperature' variations during the operation of thedevice.

A pair of metallic rods 24, which are secured 5 to the flanges 22 of theanode, extend beyond the ends of the flanges 22 and support two unitarytwin insulator assemblies. The assembly adjacent the top of theenclosing vessel Ill, as shown in Fig. 3, comprises two substantiallyparallel insulating members 25 and 26, such as glass beads or rods.These beads are rigidly connected together and spaced apart by shortwires 2! which have their ends embedded in the insulating members 25 and26, the wires 21 being attached, for instance, by spot welding atsubstantially their midpoint to the metallic rods 24 adjacent one end ofthe anode E9. The assembly adjacent the press l2, as shown in Fig. 4,likewise comprises a pair of substantially parallel insulating members28, 29 rigidly connected together and spaced by short wires 30 which aresecured to the metallic rods 24 adjacent the other end of the anode IS.

A plurality of rigid wires 31 extend between and are embedded in theinsulating members 25, 26. 5

Similar wires 32 extend between and are embedded in the insulatingmembers 28, 29. A pair of parallel rigid metallic rods 33 extend betweenand are secured to the wires 35, 32 and support the helical controlelectrode or grid 21 concentric with and uniformly spaced from the anodeiii. A pair of wires 34 are embedded in the central section of theinsulating member 25 and bent around the bead 25 to support flexiblewires 35 which carry hook members 36 engaging the bights of thevi-shaped cathode 20. The midpoint of the cathode 25 is engaged by ahook member 3i which is carried by a rigid wire 38 extending inwardlyfrom the insulating member 25. The ends of the cathode 2d are secured towire connectors Ail and 56 which are attached to wires 39, embedded inand extending from the insulating members 28. The flexible wires 35allow longitudinal expansion and contraction of the filamentary cathode28 with temperature variations during the operation of the device andmaintain the filament taut and in the proper space relation with thegrid and anode. This construction provides a compact and rigid electrodeassembly which may be readily fabricated and mounted as a unit within anenclosing vessel.

In order to prevent changes in the space relation of the electrodes byacoustic or mechanical shocks and to thereby maintain thecharacteristics of the electron discharge device uniform, the unitaryelectrode assembly described above may be resiliently supported withinthe enclosing vessel ill as described in detail hereinafter.

A U-shaped or bowed resilient support or spring member 40, which may beof fine tungsten wire, is secured at its ends to the rigid rods 24 andat its center to the rigid rod l5. In order to increase the surface areaof the spring member and insure a rigid connection between the spring itand the rods 24 and I5, a sleeve ll, for example, of nickel surroundsthe spring ll! at the points of contact with the rods 24 or iii as shownn Fig. 5. This sleeve may be easily welded to the support rods withoutdanger of weakening the fine spring member by corrosion or melting. Aleading-in wire 42 is embedded in the stem ll and electrically connectsthe rod l to one of the terminal prongs M so that the rod l5 and r thesupport All serve as current supply connec tions for the anode l9.

Another bowed or U-shaped support or spring member 33, of fine tungstenwire, is secured to rod l6 and to the grid supporting rods 33'by spotwelding, through metallic sleeves M similar to the sleeve ll. Aleading-in wire 45 embedded in the stem ll electrically connects the rodit to one of the terminal prongs Hi so that an electri cal connection isestablished between the grid 2i and one of the termmals l through thesupport A pair of resilient circular or elliptical supports or springmembers 35, ll of tungsten wire, are secured to the bent wires 61, i8respectively, for example, by spot welding through metallic sleeves 38as shown in Fig. 6, and encircle the rigid rods 55, 5E. The supports 4%,ti are similarly secured to this short wire connectors Q9, 5!;respectively, with the aid of nickel sleeves 53. Current is supplied tothe cathode 29 through the circular or elliptical supports i5, ll andthrough leading-in wires 55, 52 embedded in the stem H and electricallyconnected to the bent wires ll, l8 and to certain of the terminal prongsl4.

. The resilient supports, 48, 43, 46 and all protect the electrodeassembly against acoustic and mechanical shocks so that the electrodesare maintained in the proper space relation, microphonic disturbancesare eliminated, and undistorted reproduction is realized with thedevice.

The resilient supports may be utilized so that the electrode assemblyWill have a predetermined natural frequency of vibration substantiallythe same as the resonant frequency of a circuit in which the device isto be employed. This is accomplished by regulating the stiffness,diameter and length of the spring members to achieve the desired result.

Although a specific embodiment of the invention is disclosed anddescribed herein, it is to be understood that many modifications may bemade in the structural assembly of the device without departing from thespirit and scope of this invention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising an enclosing vessel having astem, an electrode as-' sembly including an anode, a cathode resilientlyand insulatingly supported from said anode, and means supporting saidassembly from said stem, said means including a resilient member securedto said anode adjacent one end of said assembly and another resilientmember secured to said cathode adjacent the other end of said assembly.

2. An electron discharge device comprising an enclosing vessel having astem, a plurality of rigid rods projecting from said stem and extendinglengthwise of said enclosing vessel, a plurality of metallic connectingmembers in said stem, a unitary electrode assembly including an anode; acathode and a grid mechanically coupled to and insulated from saidanode, a resilient member extending from one of said rigid rods andsecured to said anode at one end of'said assembly, a resilient memberextending from another of said rods and secured to the grid at the sameend of said assembly, and a plurality ofresilient members extending fromsaid connecting members and secured to said cathode adjacent the otherend of said assembly.

3. An electron discharge device in accordance with claim 2 in which theresilient members serve as current conductors for said anode, grid andcathode.

4. An electron discharge device comprising a. unitary electrode assemblyincluding an anode, a plurality of spaced insulating members supportedfrom said anode at opposite ends thereof, a plurality of electrodescooperatively associated with said anode, mounted between said membersand supported thereby, and means mounting said assembly within saidvessel, said means including a resilient member secured to said assemblyadjacent one longitudinal extremity thereof, and another resilientmember secured to said assembly adjacent the opposite longitudinalextremity thereof.

5. An electron discharge device comprising an enclosing vessel having astem, a unitary electrode assembly including an anode, twin insulatingmembers mounted on said anode at opposite ends thereof, a grid supportedby said members within said anode, a filamentary cathode within saidanode and grid resiliently supported between certain of said members,and means for resili ently supporting said assembly from said stem, saidmeans including electrically independent flexible members associatedwith said anode, grid and cathode and serving as current conductorstherefor.

6. An electron discharge device comprising an enclosing vessel having astem, a plurality of rigid members extending from said stem, a unitaryelectrode assembly including an anode, a pair of insulating membersmounted on said anode at each end thereof, and a cathode and a gridsupported between said insulating members, resilient members adjacentone end of said assembly extending from said anode and said grid toindividual rigid members, and resilient members adjacent the other endof said assembly extending between said cathode and other individualrigid members.

'7. An electron discharge device in accordance with claim 6 in which theresilient members are bowed springs and serve as current conductors forsaid cathode, grid and anode.

8. An electron discharge device comprising an enclosing vessel having astem, leading-in conductors embedded in said stem, an anode beyond saidstem, a cathode and grid mechanically coupled to and insulated from saidanode, resilient means attached to said anode and grid and connected toindividual leading-in conductors, and looped resilient means attached tosaid cathode and other leading-in conductors and surrounding said anodeand grid leading-in conductors.

9. An electron discharge device comprising an enclosing vessel having astem, a unitary electrode assembly including an anode, sets ofinsulating beads positioned at opposite ends of said anode, meansconnecting said beads to said anode, a helical grid within said anode,supporting means extending between individual sets of beads attached tosaid grid, a filamentary cathode within said grid and anode, supportingmeans extending between one set of beads for connection to said cathodeat one end of said anode, bent Wires extending from an individual beadof the other set of beads, flexible connections from said Wires to saidcathode at the opposite end of said anode, rigid rods projecting fromsaid stem outside the boundary of said unitary assembly, arouateresilient springs connected to said rods and anode and gridrespectively, and closed looped resilient springs connected to saidcathode and stem and surrounding said rigid rods.

10. An electron discharge device in accordance with claim 9, in whichmetallic sleeves surround the resflient springs at the point of contactwith the rigid rods.

CARL I. BAKER.

